The hard question is how to put an easy-to-use self-destruction mechanism in an existing machine (only the NSA can make a customized machine), and, at the same

The hard question is how to put an easy-to-use self-destruction mechanism in an existing machine (only the NSA can make a customized machine), and, at the same time, ensure the safety of the self-destruction mechanism. A self-destruction button is a safety risk if it can be triggered accidentally or maliciously, on the other hand, a secured self-destruction button is a safety risk if it's too hard to trigger. The NSA laptops have two buttons on one side of the machine, to destruct crypto keys, one needs to open a cover and press two buttons simultaneously. It's a pretty good self-destruction button. But you cannot find it in your laptops. Or perhaps you can design your kill switch like the Russian nuclear Dead Hand - the automatic nuclear retaliation mechanism is only armed if a safety switch has been explicitly switched on, in peacetime, the switch is turned off to avoid an accidental nuclear apocalypse. But remember to arm the switch every time you travel with your laptop became a question.